I'm having a problem with my code. I know that it has to do something with a Count constructor and its parameters. However, I can't wrap my mind around it.
What parameters should I add to the Count constructor to make the code work?
import java.util.Scanner;
public class CH9Assignment
{
public static void main (String [] args)
{
count();
//Create Scanner object
Scanner input = new Scanner (System.in) ;
System.out.println ("Enter a sentence:");
String s1 = input.nextLine();
System.out.println ("Enter 1 to count characters, 2 to count words");
int x = input.nextInt();
if (x == 1)
System.out.println ("There are " + s1.length() + "characters");
}
public static int count(String word)
{
if (word == null || word.isEmpty())
{
return 0;
}
int wordCount = 0;
boolean isWord = false;
int endOfLine = word.length() - 1;
char[] characters = word.toCharArray();
for (int i = 0; i < characters.length; i++)
{
if (Character.isLetter(characters[i]) && i != endOfLine)
{
isWord = true;
}
else if (!Character.isLetter(characters[i]) && isWord)
{
wordCount++; isWord = false;
}
else if (Character.isLetter(characters[i]) && i == endOfLine)
{
wordCount++;
}
if (x == 2)
System.out.println ("There are " + wordCount + "words");
}
}
}
You only have one method called count, it requires a String parameter, yet you try to call it without parameters.
import java.util.Scanner;
public class CH9Assignment
{
public static void main (String [] args)
{
// count(); --> DELETE THIS CALL, you don't have such a method
//Create Scanner object
Scanner input = new Scanner (System.in) ;
System.out.println ("Enter a sentence:");
String s1 = input.nextLine();
int result = count(s1); // ADD THIS LINE
System.out.println ("Enter 1 to count characters, 2 to count words");
int x = input.nextInt();
if (x == 1)
System.out.println ("There are " + s1.length() + "characters");
}
// Your count method
}
This will solve the compilation issues. You should be able to work out the logical issues.
You have to call the count method with something as a parameter. So just call it with s1 as parameter inside the if block. Your count method also seems too big and blown up. So I changed it, to just split the string by a simple regex. Try the following snippet:
public static void main (String [] args){
//Create Scanner object
Scanner input = new Scanner (System.in) ;
System.out.println ("Enter a sentence:");
String s1 = input.nextLine();
System.out.println ("Enter 1 to count characters, 2 to count words");
int x = input.nextInt();
switch(x){
case 1;
System.out.println ("There are " + s1.length() + " characters");
return;
case 2:
System.out.println ("There are " + count(s1) + " words");
return;
}
}
public static int count(String word){
if(word == null || word.isEmpty()){
return 0;
}
return word.split("(\\s|\\S)+").length;
}
Related
Hi this code is part of my code that is supposed to check if the number string is palindrome.
I want to iterate from top to botoom of my code but it doesn't iterate at all , what is wrong ??
I searched in youtube and realized this kind of things , people usually use do-while loop so I was trying to follow the instruction but it doesn't give me what I want .
do {
System.out.println("You passed Catch-Block stage! , Please enter the number that you want to check if it is palindrome");
String str = kbd.nextLine().trim();
String org_str = str;
String rev = "";
int len = str.length();
for (int i = len - 1; i >= 0; i--) {
rev = rev + str.charAt(i);
}
if (org_str.equals(rev)) {
System.out.println(org_str + " is Palindrome Number");
} else {
System.out.println(org_str + "is Not Palindrome String");
}
System.out.println("Do you want to continue Y or N");
choice = kbd.next().charAt(0);
}while(choice=='y'||choice =='Y');
}
Here is my full code.
package com.company;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner kbd = new Scanner(System.in);
char choice;
long firstNum = 0;
firstNum = getLong(" Enter the first number: ", '-');
do {
System.out.println("You passed Catch-Block stage! , Please enter the number that you want to check if it is palindrome");
String str = kbd.nextLine().trim();
String org_str = str;
String rev = "";
int len = str.length();
for (int i = len - 1; i >= 0; i--) {
rev = rev + str.charAt(i);
}
if (org_str.equals(rev)) {
System.out.println(org_str + " is Palindrome Number");
} else {
System.out.println(org_str + "is Not Palindrome String");
}
System.out.println("Do you want to continue Y or N");
choice = kbd.next().charAt(0);
}while(choice=='y'||choice =='Y');
}
public static long getLong(String prompt, char exitChar)
{
long retVal = 0;
boolean validInput = false;
String userInput = "";
Scanner kbd = new Scanner(System.in);
while (!validInput) {
System.out.println(prompt);
try
{
userInput = kbd.nextLine().trim();
if (userInput.length() > 0 && userInput.charAt(0) == exitChar)
{
System.out.println("Ending the program at the user's request");
System.exit(1);
}
retVal = Long.parseLong(userInput);
validInput = true;
}
catch (Exception ex)
{
System.out.println("That is not numeric. Try again or press " + exitChar + "to Quit");
}
}
return retVal;
}
}
Change this:
String str = kbd.nextLine().trim();
to this
String str = kbd.next();
When read choice, using nextLine() intead of next():
do {
System.out.println("You passed Catch-Block stage! , Please enter the number that you want to check if it is palindrome");
String str = kbd.nextLine().trim();
String org_str = str;
String rev = "";
int len = str.length();
for (int i = len - 1; i >= 0; i--) {
rev = rev + str.charAt(i);
}
if (org_str.equals(rev)) {
System.out.println(org_str + " is Palindrome Number");
} else {
System.out.println(org_str + "is Not Palindrome String");
}
System.out.println("Do you want to continue Y or N");
choice = kbd.nextLine().charAt(0); // <---here, change to nextLine()
}while(choice=='y'||choice =='Y');
}
next() can read the input only till the space. It can't read two words separated by space. Also, next() places the cursor in the same line after reading the input. so in next loop it reads last input line that will be empty string.
I'm making a program for class which prints out the number of vowels in a word and any help would be appreciated. Currently, the program prints out the correct number of vowels but also prints out the print statement, "vowels:" multiple times before. I've tried moving the print statement and the braces around but it says "error: 'else if' without 'if'". I'm completely new to Java so sorry if the solution is in plain sight. Thank you in advance :)
import java.util.Scanner;
public class Main
{
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print("Enter text: ");
String text = input.nextLine();
text = text.toLowerCase();
int vowels= 0;
int l;
l= text.length();
for (int i = 1; i < text.length(); i++) {
String wordPRT = text.substring(i,i+1);
if (wordPRT.compareToIgnoreCase("a")==0 || wordPRT.compareToIgnoreCase("e")==0||
wordPRT.compareToIgnoreCase("i")==0
|| wordPRT.compareToIgnoreCase("o")==0
|| wordPRT.compareToIgnoreCase("u")==0){
vowels++;
System.out.println("vowels: " + vowels);
}
else if(vowels<1){
System.out.print("no vowels");
}
}
}
}
You are printing everything in a for loop instead of count vowels and print at the end.
try something like:
int vowelsCounter = 0;
for(...) {
... logic to count the vowels
if(isvowel(string.charAt(i)){
vowelsCountr++;
}
}
if(vowelsCounter > 0 ) {
printSomething
}
else {
print something else
}
Also You should not use subString for this kind of a loop but string.charAt(i)
Move the print statements out of the for loop.
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print("Enter text: ");
String text = input.nextLine();
text = text.toLowerCase();
int vowels = 0;
int l;
l = text.length();
for (int i = 1; i < text.length(); i++) {
String wordPRT = text.substring(i, i + 1);
if (wordPRT.compareToIgnoreCase("a") == 0 || wordPRT.compareToIgnoreCase("e") == 0
|| wordPRT.compareToIgnoreCase("i") == 0 || wordPRT.compareToIgnoreCase("o") == 0
|| wordPRT.compareToIgnoreCase("u") == 0) {
vowels++;
}
}
if (vowels >= 1) {
System.out.println("vowels: " + vowels);
} else {
System.out.print("no vowels");
}
}
}
A sample run:
Enter text: Hello
vowels: 2
I am attempting to write a program that picks a random word from a text file, scrambles it, and allows the user to unscramble it by swapping 2 index locations at a time.
I have the program to the point where it grabs a random word from the text file and prints it out with the index numbers above it.
I am having trouble figuring out how to:
Get the word scrambled before it prints out on screen, and
How to get the user to be able to loop through swapping 2 indexes at a time until the word is unscrambled.
Is there a method I can write that will perform these actions?
Here is my code so far.
import java.io.*;
import java.util.*;
public class Midterm { // class header
public static void main(String[] args) { // Method header
int option = 0;
Scanner input = new Scanner(System.in);
int scrambled;
int counter = 0;
int index1;
int index2;
String[] words = readArray("words.txt");
/*
* Picks a random word from the array built from words.txt file. Prints
* index with word beneath it.
*/
int randWord = (int) (Math.random() * 11);
for (int j = 0; j < words[randWord].length(); j = j + 1) {
System.out.print(j);
}
System.out.print("\n");
char[] charArray = words[randWord].toCharArray();
for (char c : charArray) {
System.out.print(c);
}
/*
* Prompt the user for input to play game or quit.
*/
System.out.println("\n");
System.out.println("Enter 1 to swap a par of letters.");
System.out.println("Enter 2 to show the solution and quit.");
System.out.println("Enter 3 to quit.");
if (input.hasNextInt()) {
option = input.nextInt();
counter++;
}
else {
option = 3;
}
System.out.println("");
if (option == 1) {
System.out.println("Enter the two index locations to swap separated by a space. ");
index1 = 0;
index2 = 0;
if (input.hasNextInt()) {
index1 = input.nextInt();
}
else {
System.out.println("Please enter only numbers.");
}
if (input.hasNextInt()) {
index2 = input.nextInt();
}
else {
System.out.println("Please enter only numbers.");
}
}
}
// end main
public static String[] readArray(String file) {
// Step 1:
// Count how many lines are in the file
// Step 2:
// Create the array and copy the elements into it
// Step 1:
int ctr = 0;
try {
Scanner s1 = new Scanner(new File(file));
while (s1.hasNextLine()) {
ctr = ctr + 1;
s1.nextLine();
}
String[] words = new String[ctr];
// Step 2:
Scanner s2 = new Scanner(new File(file));
for (int i = 0; i < ctr; i = i + 1) {
words[i] = s2.next();
}
return words;
} catch (FileNotFoundException e) {
}
return null;
}
}
I made some pretty major modifications to your code, including adding a scrambler method. The program is almost perfect, its just that your file "words.txt" can not hold words with repeat letters. For example, yellow, green, and purple won't unscramble correctly, but white, gray, blue, orange, or red will work fine. Other than that, the program works well. It chooses a random word, then when it is solved, chooses a different word, changing the last word to null, so it does not get picked again. Here's the program:
import java.io.*;
import java.util.*;
public class Experiments { // class header
private static String[] words = readArray("/Users/UserName/Desktop/words.txt"); //change to your location of the file
public static void main(String[] args) { // Method header
int option = 0;
Scanner input = new Scanner(System.in);
int counter = 0;
String scrambledWord;
int index1;
int index2;
Random rand = new Random();
int randWord = rand.nextInt(words.length);
for (int j = 0; j < words[randWord].length(); j += 1) {
System.out.print(j);
}
System.out.print("\n");
scrambledWord = scrambler(words[randWord]);
System.out.println(scrambledWord);
System.out.println("\n");
System.out.println("Enter 1 to swap a pair of letters.");
System.out.println("Enter 2 to show the solution and quit.");
System.out.println("Enter 3 to quit.");
option = input.nextInt();
if (option == 1) {
while (!scrambledWord.equals(words[randWord])) {
index1 = 0;
index2 = 0;
boolean validOption = false;
System.out.println("Enter the two index locations to swap separated by a space.");
while (!validOption) {
if (input.hasNextInt()) {
index1 = input.nextInt();
index2 = input.nextInt();
validOption = true;
}
else {
System.out.println("Please enter only numbers.");
validOption = false;
break;
}
}
String letter1 = scrambledWord.substring(index1, index1+1);
String letter2 = scrambledWord.substring(index2, index2+1);
System.out.println("replacing " + letter1 + " with " + letter2 + "...");
if (index1 < index2) {
scrambledWord = scrambledWord.replaceFirst(letter2, letter1);
scrambledWord = scrambledWord.replaceFirst(letter1, letter2);
} else {
scrambledWord = scrambledWord.replaceFirst(letter1, letter2);
scrambledWord = scrambledWord.replaceFirst(letter2, letter1);
}
System.out.println();
for (int j = 0; j < words[randWord].length(); j += 1) {
System.out.print(j);
}
System.out.println("\n"+scrambledWord);
System.out.println();
counter++;
if (scrambledWord.equals(words[randWord])){
System.out.println("You did it! The word was " + words[randWord]);
System.out.println("You got it with " + counter + " replacements!");
words[randWord] = null;
if (words.length == 0){
System.out.println("I'm all out of words. You win!");
System.exit(0);
} else {
main(args);
}
}
}
} else if (option == 2) {
System.out.println(words[randWord]);
System.exit(0);
} else {
System.exit(0);
}
input.close();
}
//scrambles the word given to it
private static String scrambler(String word) {
String scrambled = "";
Random rand = new Random();
int length;
int index;
String letter;
String firststring;
String secondstring;
while (word.length()>0) {
length = word.length();
index = rand.nextInt(length);
letter = word.substring(index, index+1);
firststring = word.substring(0, index);
secondstring = word.substring(index+1);
word = firststring + secondstring;
scrambled += letter;
}
return scrambled;
}
public static String[] readArray(String file) {
int ctr = 0;
try {
Scanner s1 = new Scanner(new File(file));
while (s1.hasNextLine()) {
ctr = ctr + 1;
s1.nextLine();
}
String[] words = new String[ctr];
// Step 2:
Scanner s2 = new Scanner(new File(file));
for (int i = 0; i < ctr; i = i + 1) {
words[i] = s2.next();
}
return words;
} catch (FileNotFoundException e) {
e.printStackTrace();
}
return null;
}
}
And here's the list of words in the file words.txt(I pretty much wrote down whatever popped into my head that did not have repeat letters):
orange
red
brown
black
white
blue
tiger
horse
bugs
stack
overflow
pathfinder
extra
zealous
wisdom
under
above
death
life
second
first
frost
forest
These are obviously not the only words that can go in, you can add as many as you want, as long as they do not have 2 occurrences of the same letter.
You are reading the file incorrectly. Do
public static String[] readArray(String file) {
int ctr = 0;
try {
Scanner s1 = new Scanner(new File(file));
while (s1.hasNext()) {
ctr = ctr + 1;
s1.next();
}
//..rest of code
import java.util.*;
public class HangManP5
{
public static void main(String[] args)
{
int attempts = 10;
int wordLength;
boolean solved;
Scanner k = new Scanner(System.in);
System.out.println("Hey, what's your name?");
String name = k.nextLine();
System.out.println(name+ ", hey! This is a hangman game!\n");
RandomWord(word);
int len = word.length();
char[] temp = new char[len];
for(int i = 0; i < temp.length; i++)
{
temp[i] = '*';
}
System.out.print("\n");
System.out.print("Word to date: ");
while (attempts <= 10 && attempts > 0)
{
System.out.println("\nAttempts left: " + attempts);
System.out.print("Enter letter: ");
String test = k.next();
if(test.length() != 1)
{
System.out.println("Please enter 1 character");
continue;
}
char testChar = test.charAt(0);
int foundPos = -2;
int foundCount = 0;
while((foundPos = word.indexOf(testChar, foundPos + 1)) != -1)
{
temp[foundPos] = testChar;
foundCount++;
len--;
}
if(foundCount == 0)
{
System.out.println("Sorry, didn't find any matches for " + test);
}
else
{
System.out.println("Found " + foundCount + " matches for " + test);
}
for(int i = 0; i < temp.length; i++)
{
System.out.print(temp[i]);
}
System.out.println();
if(len == 0)
{
break; //Solved!
}
attempts--;
}
if(len == 0)
{
System.out.println("\n---------------------------");
System.out.println("Solved!");
}
else
{
System.out.println("\n---------------------------");
System.out.println("Sorry you didn't find the mystery word!");
System.out.println("It was \"" + word + "\"");
}
}
public static String RandomWord(String word)
{
//List of words
Random r = new Random();
int a = 1 + r.nextInt(5);
if(a == 1)
{
word=("Peace");
}
if(a == 2)
{
word=("Nuts");
}
if(a == 3)
{
word=("Cool");
}
if(a == 4)
{
word=("Fizz");
}
if(a == 5)
{
word=("Awesome");
}
return (word);
}
}
Ok, so this is my code for a hangman game, the only thing I have left to do is to get my program to randomize one of the words, which it should do in the method successfully. But the only problem I'm having is getting the String variable "word" to go back to the main class (there are errors underlining all the "word" variables in the main class).
If I could get help with either this or another way to produce a random word from a list, that would be amazing.
In java, parameters are passed by value and not by reference. Therefore, you cannot change the reference of a parameter.
In your case, you need to do:
public static String getRandomWord() {
switch(new Random().nextInt(5)) {
case 0:
return "Peace";
case 1:
return "Nuts";
// ...
default:
throw new IllegalStateException("Something went wrong!");
}
}
And in main:
// ...
String word = getRandomWord();
int len = word.length();
// ...
You can't modify the caller's reference.
RandomWord(word);
needs to be something like
word = RandomWord(word);
Also, by convention, Java methods start with a lower case letter. And, you could return the word without passing one in as an argument and I suggest you save your Random reference and use an array like
private static Random rand = new Random();
public static String randomWord() {
String[] words = { "Peace", "Nuts", "Cool", "Fizz", "Awesome" };
return words[rand.nextInt(words.length)];
}
And then call it like
word = randomWord();
I am trying to make a text-based Hangman in Java.
This is my Java code:
package hangman;
import java.util.Random;
import java.util.Scanner;
import java.lang.String;
public class Hangman {
public static void main(String[] args) {
// TODO code application logic here
Scanner chez = new Scanner(System.in);
Scanner waffle = new Scanner(System.in);
Random randomGenerator = new Random();
StringBuilder displayWord = new StringBuilder("______________________________");
String theWord = null;
String preLetter;
//String sbDisplayWord;
char letter = 0;
int randomNumber;
int lengthOfWord;
int numberOfLetterInWord = 0;
int gDisplay;
int guessWordNumber = 0;
String guessWord;
RandomWord troll = new RandomWord();
randomNumber = randomGenerator.nextInt(12);
//Fill var with the word.
theWord = troll.wordDecide(randomNumber);
System.out.println ("Welcome to Hangman!");
lengthOfWord=theWord.length( );
System.out.println("This word has " + lengthOfWord + " letters.");
System.out.println("You have 20 guesses.");
for (int g =19; g >= 0; g--) {
System.out.println("If you want to guess the word, type 0. If you want to guess a letter, type 1.");
guessWordNumber=chez.nextInt();
if (guessWordNumber==0) {
System.out.println("Enter the word now. Remember, don't capitalize it.");
guessWord=waffle.nextLine();
if (guessWord.equals(theWord)) {
System.out.println("YOU WIN");
System.exit(0);
} else {
System.out.println("Sorry, this wasn't the correct word.");
}
} else if (guessWordNumber==1) {
System.out.println("Please enter the letter you wish to guess with.");
//System.out.println("It will tell you if you have guessed right for any of the letters. If it is blank, that means none of the letters match.");
preLetter=chez.nextLine();
letter=preLetter.charAt(0);
System.out.println("");
for(int i = 0; i <= lengthOfWord -1; i++ ) { //-Eshan
if (letter == theWord.charAt( i )) {
numberOfLetterInWord=i+1;
System.out.println("This letter matches with letter number " + numberOfLetterInWord + " in the word.");
displayWord.setCharAt(i, letter);
} else {
numberOfLetterInWord=i+1;
System.out.println("This letter doesn't match with letter number " + numberOfLetterInWord + " in the word.");
}
}
System.out.println("");
System.out.println("The word so far is " + displayWord);
System.out.println("");
gDisplay = g + 1;
System.out.println("You have " + gDisplay + " guesses left.");
} else {
System.exit(0);
}
}
System.out.println("GAME OVER");
System.exit(0);
}
}
package hangman;
public class RandomWord {
private static String[] wordArray = {
"psychology",
"keratin",
"nostalgia",
"pyromaniac",
"chlorophyl",
"derivative",
"unitard",
"pterodactyl",
"xylophone",
"excommunicate",
"obituary",
"infinitesimal",
"concupiscent",
};
public String wordDecide(int randomNumber) {
String theWord;
theWord = wordArray[randomNumber];
return theWord;
}
}
Netbeans is giving me this error:
Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: 0
at java.lang.String.charAt(String.java:695)
at hangman.Hangman.main(Hangman.java:56)
Java Result: 1
This is probably happening when you call charAt(0) on a string of length 0. You should check to see that the string is not empty before calling the method.
You are getting a StringIndexOutOfBoundsException due to the fact the line
guessWordNumber = chez.nextInt();
does not consume newline characters and passes the character through to the line
preLetter = chez.nextLine();
which then doesn't block as it will have already received input. This assigns an empty String to preLetter resulting in the exception. You can use Scanner#nextLine to consume this character:
guessWordNumber = Integer.parseInt(chez.nextLine());